I heard a loud rotor noise yesterday am and assumed it was the local medevac landing at the park. The noise lasted longer than usual so I went to check it out. It turned out to be a commercial S-58T (Aris Helicopters) lifting containers of some sort up to the roof of the local shopping mall. The mall is 3/4 miles from me and the helo was still loud. While I was watching the helo going back and forth for new cargo, I noticed that several cars had pulled into the parking lot to watch the helo work. A good way to start the morning!

I checked and the helo N58AH was a former French AF H-34. Too bad it wasn't Marine. 🙁

According to Appendic C in Lennart Lundh's excellent "Sikorsky H-34 An Illustrated History", the turbine version S-58T has a max speed of 138mph at sea level vs 120 for the piston-engine versions. Cruising speed is also better; 127mph for the S-58T/ 97mph for the H-34.

S58T (H34 with twin pack PT6)

Got my data out of my files (piles of them). I was on the conversion program in 1968 and went to PA at Carsons Farm to install the first PT-6 twin pack kit in the H34 helicopter. Carson Helicopters later had a large fleet of Helicopters. Will give you the Data requested: (Standard Temp at 13000 Lbs) Speed- Cruise 110 Knts, Max 120 Knts (The speed was limited by the rotor configuration not the power available). Hover Cieling IGE, 8,950 Ft. Single engine Ceiling2,100 Ft, Fuel consumption, 106 gal per hour. Range with 20 minute warning, 283 Gallon fuel 290 Miles. Power, Takeoff 5 minutes 1800 SHP. 30 minute power 1800 SHP. Max continuous 1600 SHP. Max Gross Wt, 13,000 Lbs. Useful load, 5,600 Lbs. Wt empty with standard Equipment, 7,400 Lbs. Fuselage length 50'11", Fuselage width 5'8", Height to top of tail rotor 15'11", M rotor Diamater 56 ft, Tail Diameter 9'6", Main Gear tread 12', Cabin Height 5'9". Hope this is not more than what you needed!! 🙂 SF PM PS. Yes , Sikorsky purchased a group of H34 as I remember about 18 or 20. My Friend Retired Marine MSgt John Kindyabal went to France & made the buy. They were converted to Twin Pack S58T and sold world wide, Some in Canada, Australia, Thialand and of course in the U.S. A. . The first one I converted was sold in Canada to set up power line towers. It crashed & burned and I was on my way to investigate. Was not needed a bystander was filming the operation and was killed by Main Blade weights from the crash. His camera recorded the wts coming at him that killed him. It showed that the tower was dragged to the cement platfom where it hooked and pulled the helicopter into the ground. Tower should have been lifted and than placed on the platform.

H-34 Speed

PM is right. Max speed is related to the rotor configuration, a fully articulated rotor head. There was a NATOPS plate on the instrument panel of the UH-34D that stated DO NOT EXCEED 126 knots. That of course was for powered flight. Decent with zero blade pitch, such as autorotation, you could get more. The main limiting factor was "Retreating Blade Stall". The odd thing about helicopters is that the faster you go, the closer you come to stalling (retreating blade stall). To get more airspeed you have to increase the blade speed. Unfortunately, the H-34 blade speed could not be appreciably increased without overstressing the metal in the main spar and causing metal fatigue which would lead to having a VERY BAD DAY.

"Crazy Joe" Scholle
HMM-363